WO2001044715A1 - Backlight for lcd's - Google Patents

Backlight for lcd's Download PDF

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Publication number
WO2001044715A1
WO2001044715A1 PCT/EP2000/012537 EP0012537W WO0144715A1 WO 2001044715 A1 WO2001044715 A1 WO 2001044715A1 EP 0012537 W EP0012537 W EP 0012537W WO 0144715 A1 WO0144715 A1 WO 0144715A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
guide plate
lamp
light guide
light sources
Prior art date
Application number
PCT/EP2000/012537
Other languages
French (fr)
Inventor
Mitsuteru Akiho
Original Assignee
Koninklijke Philips Electronics N.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Priority to EP00981365A priority Critical patent/EP1161639B1/en
Priority to DE60040972T priority patent/DE60040972D1/en
Publication of WO2001044715A1 publication Critical patent/WO2001044715A1/en
Priority to US09/932,102 priority patent/US7025488B2/en

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/0031—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/0068—Arrangements of plural sources, e.g. multi-colour light sources

Definitions

  • This invention relates to an illumination device for display device and more particularly to an illumination device for a liquid crystal display apparatus, which is referred to a backlight.
  • a backlight system is used to illuminate a display surface from a back of an LCD panel A user can see a display image clearly under the environment which ambient light is dim according to this system
  • the backlight system desc ⁇ bed in this publication composes a reflecting mirror for cove ⁇ ng these lamps to reflect light emitted from the light source to a light guide section using four elongated lamps as a light source on one side end of the LCD panel Moreover, these four lamps are arranged such that a distance from the side end of the panel is different each other.
  • Such arrangement manner makes a parasitic capacitance (a floating capacitance) of each of lamp caused by a lamp operation environment, specifically, a different gap from the reflecting m.rror.
  • a parasitic capacitance a floating capacitance
  • an amount of current flow of one lamp becomes higher than the amount of current flow o ⁇ ⁇ the other lamp, so that different life times of the lamps may be occurred.
  • the life time of the lamp depends on the amount of current flow through the lamp, and it can be said that the life time of a lamp is short in case that excessive current has been fed to the lamp.
  • the object of the invention is to provide a display apparatus illumination device which the same current can be fed to the lamp or the like under the same driving voltage, thereby to be able to contribute to a longer life time of the lamp.
  • an illumination device for display device comprises a light guide plate, three or more light sources provided around at least one of side ends of the light guide plate, and a light reflection member, surrounding said light sources, that reflects light emitted from said light sources to said light guide plate, wherein said light sources are provided so as to have the same parasitic capacitance caused by intervals or gaps between said light sources and said light reflection member.
  • At least one of said light sources positioned at the center is closer to an end of said light reflection member farthest from said light guide plate than the other light sources. Because of this constitution, the parasitic capacitance of the lamps can be made equal effectively.
  • the light reflection member has an opening faced to the side end of the light guide plate, and wherein the light sources are accommodated inside said light reflection member so as to emit light from the opening to the light guide plate. So a light reflecting function and a light source accommodating said function can be constituted by the same member.
  • the light guide plate is provided on a rear surface side of a display panel of a transmission liquid crystal display device, and has a light reflection layer on a surface on the opposite side to the liquid crystal display device. So it can be applied as the backlight of the transmitting-type liquid crystal display apparatus.
  • the light sources are elongated lamps provided in approximately parallel to each other along the side end of the light guide plate.
  • Fig. 1 schematically shows a part of a backlight system for the transmitting- type liquid crystal display apparatus as an illumination device according to one embodiment of the invention.
  • this backlight system 1 comprises a light guide plate 10 arranged on the rear surface side of a transmission type LCD panel 2, a light reflecting plate (a layer) IR arranged on the rear surface of this light guide plate 10, three pieces of lamp 11, 12 and 13 arranged at the vicinity of the side of the light guide plate 10, and a reflector 19 surrounding these lamps wholly and having a light-reflecting surface on the inside surface.
  • the LCD panel 2 comprises two transparent substrates sandwiching and holding an enclosed liquid crystal therebetween, a matrix of thin film transistors connected with a pixel electrode and formed on one of the substrate, common electrodes and color filter layers formed on the other of the substrates, and optical films.
  • the light emitted from the lamp is entered into the light guide plate 10 directly, or after being reflected by a reflector 19, and to be subjected to a light diffusion action in the light guide plate 10 together with further a reflex action by a light reflection plate IR, and then to be led to the LCD panel 2.
  • the first, second, and third lamps 11, 12 and 13 are the elongated lamps extended in the direction perpendicular to a paper of the drawing respectively, and for example, a fluorescent lamp tubes such as cold cathode discharge tubes, or hot-cathode discharge tubes are applied. Although such lamps are arranged along the side of the light guide plate 10 and in parallel each other, only the second lamp 12 at the central is arranged closer to the reflector 19.
  • the lamp of the first or the third is arranged such that the parasitic capacitance (floating capacitance) of the lamps caused by the gap of the lamp and the reflector 19 become equal each other.
  • the inventor has recognized that at least one lamp at the central is kept away from the side of the panel than other lamps and is arranged closer to the reflector 19b, whereby the parasitic capacitances can be equalized effectively.
  • a total parasitic capacitance Cl may contain a parasitic capacitance Cla formed in the gap between the first surface 19a of the reflector 19 and the lamp 11 and a parasitic capacitance Clb formed in the gap between the second surface 19b thereof and the lamp 1 l,in the case of this embodiment that the reflector 19 is a rectangle.
  • a total parasitic capacitance C2 may contain a parasitic capacitance C2a formed in the gap between the first surface 19a and the lamp 12, a parasitic capacitance C2b formed in the gap between the second surface 19b and the lamp 12, and a parasitic capacitance C2c formed in the gap between the third surface 19c and the lamp 12.
  • a total parasitic capacitance C3 may contain a parasitic capacitance C3b formed in the gap between the second surface 19b and the lamp 13, and a parasitic capacitance C3c formed in the gap between the third surface 19c and the lamp 13.
  • the same current can be fed through all lamps by the above-mentioned arrangement of the lamps when driving each lamp with the same voltage.
  • the reflector 19 has a symmetric cross-section shape with respect to a central line "q”
  • the arrangement of the lamp also may be symmetric, whereby the arrangement becomes easy.
  • the unbalanced parasitic capacitance can be reduced by the arrangement, whereby the life time of the lamp can be longer, and the life time of the display devices can be longer.
  • the arrangement of the lamp may be determined for the same parasitic capacitance of the lamps by considering the parasitic capacitance of each lamp with respect to the entire region of the reflecting surface of the reflector 19'. In this case, it is also effective that the lamp 12 at the central is closer to a portion of the reflector 19' which portion is farthest from the light guide 10.
  • Fig. 3 schematically shows a part of a backlight system for the transmitting- type liquid crystal display apparatus as an illumination device in the further embodiment of the invention.
  • the same reference symbols are referred to the same portions as Fig.
  • This backlight system 1 has four lamps, but the arrangement may be considered in a similar way. That is, the second and the third lamps 12 and 13 at the central are closer to a portion of the reflector 19 which portion is farthest from the light guide 10. According to this constitution, the parasitic capacitance of four lamps can be equalized effectively, and the same effect as the constitution of Fig. 1 may be obtained. Moreover, even though the reflector is of a half-round shape in the cross section as shown in Fig. 4, the similar effect can be obtained in a similar way. Although only the three and four lamps are explained in the embodiments, the parasitic capacitances can be equalized effectively in the same way also for more lamps.
  • the inverter circuit for driving the lamps is easily designed and may be advantageous for size reduction.
  • the luminance control is also easy. Since luminance is low as compared with a lamp of the hot-cathode discharge tube, high luminance may be obtained by using many lamps. In such case, the illumination device according to this invention is very suitable.
  • a parabolic shape or a trapezoid shape may be applicable.
  • the same effect can be obtained by the arrangement for the same parasitic capacitance of all lamps in case of the backlight system using three or more lamps.
  • the invention should not be limited to the LCD apparatus. This invention is applicable for other kind of display apparatus using the illumination device. Furthermore, although the backlight system of the transmitting-type LCD apparatus with an active matrix type using thin film transistors has been described in the embodiments, the invention is also applicable for an apparatus with a simple matrix type, and it is also applicable for the illumination system as a subsidiary illumination in a reflective type of LCD apparatus. A light reflective plate IR described in the embodiment may be changed in such illumination system.
  • the same amount of lamp current can be fed when applying the same driving voltage to each light source. Therefore, an approximately uniform luminance can be obtained for each lamp. Moreover, by equalizing a parasitic capacitance of a lamp, an excessive lamp current can be prevented and a life time of a lamp is longer so that the longer life time of products can be realized.
  • FIG. 1 diagramatically shows a paitial section view for a backlight system as an illumination device according to the invention.
  • Fig. 2 shows a section view for a further embodiment of the backlight system.
  • Fig. 3 shows a partial section view for a further backlight system as an illumination device according to the invention.
  • Fig. 4 shows a section view for a further backlight system.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Planar Illumination Modules (AREA)
  • Liquid Crystal (AREA)

Abstract

The device has a light guide plate (10), three or more light sources (11, 12) and (13) provided around at least one of side ends of the light guide plate (10), and a light reflection member (19), surrounding these light sources, to reflect light emitted from the light sources to the light guide plate (10). The light sources (11, 12) and (13) are located so as to have the same parasitic capacitance caused by intervals between the light sources and the light reflection member (19).

Description

Backlight for LCD's
Detailed Descπption of the Invention Technical Field of the Invention
This invention relates to an illumination device for display device and more particularly to an illumination device for a liquid crystal display apparatus, which is referred to a backlight.
Pπor Art
In a display apparatus such as a transmission LCD, a backlight system is used to illuminate a display surface from a back of an LCD panel A user can see a display image clearly under the environment which ambient light is dim according to this system
In a typical manner of such backlight system, there are a both sides lighting type and a one-sided lighting type, and vaπous devices have been devised so as to introduce uniformly light emitted by a light source to an entire screen from the side end(s) of the LCD panel. Such backlight system has been developed in Japanese patent application Laid-open No.9- 15595
The backlight system descπbed in this publication composes a reflecting mirror for coveπng these lamps to reflect light emitted from the light source to a light guide section using four elongated lamps as a light source on one side end of the LCD panel Moreover, these four lamps are arranged such that a distance from the side end of the panel is different each other. So in the arrangement that four lamps are located in the direction of the thickness of the light guide section, it is constituted that a distance to the side end of the light guide section from a first and a third lamps is short, therefore, the distance from the reflecting mirror to the first and the third lamps is long, whereas a distance to the side end of the light guide section from a second and a fourth lamps is long, therefore, the distance from the reflecting mirror to the second and the fourth lamps is short
Problems to be solved by the Invention
Such arrangement manner makes a parasitic capacitance (a floating capacitance) of each of lamp caused by a lamp operation environment, specifically, a different gap from the reflecting m.rror. According to this constitution, even if the same driving voltage is supplied to each lamp, an amount of current flow of one lamp becomes higher than the amount of current flow oϊ~ the other lamp, so that different life times of the lamps may be occurred. The life time of the lamp depends on the amount of current flow through the lamp, and it can be said that the life time of a lamp is short in case that excessive current has been fed to the lamp. Moreover, since the life time of the backlight system would be determined by the shortest lamp life time of the lamps used therein, it is important to realize the same life time of the lamps by constituting such that current can not be fed excessively and the same amount of current should be fed to each lamp under the same driving voltage. The object of the invention is to provide a display apparatus illumination device which the same current can be fed to the lamp or the like under the same driving voltage, thereby to be able to contribute to a longer life time of the lamp.
[Means for solving the problems]
To this end, an illumination device for display device according to the invention comprises a light guide plate, three or more light sources provided around at least one of side ends of the light guide plate, and a light reflection member, surrounding said light sources, that reflects light emitted from said light sources to said light guide plate, wherein said light sources are provided so as to have the same parasitic capacitance caused by intervals or gaps between said light sources and said light reflection member.
Since light sources or lamps are arranged as described above, the same amount of current can feed through the lamps when supplying the same driving voltage to each lamp. Moreover, an excessive lamp current can be avoided by unifying the parasitic capacitance of the lamp, whereby the life time of the lamp can be extended and can contribute to a longer life time of products in its turn.
In the illumination device of the described-above manner, at least one of said light sources positioned at the center is closer to an end of said light reflection member farthest from said light guide plate than the other light sources. Because of this constitution, the parasitic capacitance of the lamps can be made equal effectively.
Moreover, the light reflection member has an opening faced to the side end of the light guide plate, and wherein the light sources are accommodated inside said light reflection member so as to emit light from the opening to the light guide plate. So a light reflecting function and a light source accommodating said function can be constituted by the same member.
Moreover, the light guide plate is provided on a rear surface side of a display panel of a transmission liquid crystal display device, and has a light reflection layer on a surface on the opposite side to the liquid crystal display device. So it can be applied as the backlight of the transmitting-type liquid crystal display apparatus.
Furthermore, the light sources are elongated lamps provided in approximately parallel to each other along the side end of the light guide plate.
Embodiment of the Invention
Fig. 1 schematically shows a part of a backlight system for the transmitting- type liquid crystal display apparatus as an illumination device according to one embodiment of the invention.
In Fig. 1, this backlight system 1 comprises a light guide plate 10 arranged on the rear surface side of a transmission type LCD panel 2, a light reflecting plate (a layer) IR arranged on the rear surface of this light guide plate 10, three pieces of lamp 11, 12 and 13 arranged at the vicinity of the side of the light guide plate 10, and a reflector 19 surrounding these lamps wholly and having a light-reflecting surface on the inside surface.
The LCD panel 2 comprises two transparent substrates sandwiching and holding an enclosed liquid crystal therebetween, a matrix of thin film transistors connected with a pixel electrode and formed on one of the substrate, common electrodes and color filter layers formed on the other of the substrates, and optical films. The light emitted from the lamp is entered into the light guide plate 10 directly, or after being reflected by a reflector 19, and to be subjected to a light diffusion action in the light guide plate 10 together with further a reflex action by a light reflection plate IR, and then to be led to the LCD panel 2.
The first, second, and third lamps 11, 12 and 13 are the elongated lamps extended in the direction perpendicular to a paper of the drawing respectively, and for example, a fluorescent lamp tubes such as cold cathode discharge tubes, or hot-cathode discharge tubes are applied. Although such lamps are arranged along the side of the light guide plate 10 and in parallel each other, only the second lamp 12 at the central is arranged closer to the reflector 19.
More particularly, the lamp of the first or the third is arranged such that the parasitic capacitance (floating capacitance) of the lamps caused by the gap of the lamp and the reflector 19 become equal each other. The inventor has recognized that at least one lamp at the central is kept away from the side of the panel than other lamps and is arranged closer to the reflector 19b, whereby the parasitic capacitances can be equalized effectively.
For the first lamp 11 at one side, a total parasitic capacitance Cl may contain a parasitic capacitance Cla formed in the gap between the first surface 19a of the reflector 19 and the lamp 11 and a parasitic capacitance Clb formed in the gap between the second surface 19b thereof and the lamp 1 l,in the case of this embodiment that the reflector 19 is a rectangle. Moreover, for the second lamp 12 at the central, a total parasitic capacitance C2 may contain a parasitic capacitance C2a formed in the gap between the first surface 19a and the lamp 12, a parasitic capacitance C2b formed in the gap between the second surface 19b and the lamp 12, and a parasitic capacitance C2c formed in the gap between the third surface 19c and the lamp 12. For the third lamp 13, a total parasitic capacitance C3 may contain a parasitic capacitance C3b formed in the gap between the second surface 19b and the lamp 13, and a parasitic capacitance C3c formed in the gap between the third surface 19c and the lamp 13. The same current can be fed through all lamps by the above-mentioned arrangement of the lamps when driving each lamp with the same voltage. When the reflector 19 has a symmetric cross-section shape with respect to a central line "q", the arrangement of the lamp also may be symmetric, whereby the arrangement becomes easy. Moreover, the unbalanced parasitic capacitance can be reduced by the arrangement, whereby the life time of the lamp can be longer, and the life time of the display devices can be longer.
On the other hand, when the reflector is not a rectangle in the cross section view, but is an approximately half-round in Fig. 2, the arrangement of the lamp may be determined for the same parasitic capacitance of the lamps by considering the parasitic capacitance of each lamp with respect to the entire region of the reflecting surface of the reflector 19'. In this case, it is also effective that the lamp 12 at the central is closer to a portion of the reflector 19' which portion is farthest from the light guide 10.
Fig. 3 schematically shows a part of a backlight system for the transmitting- type liquid crystal display apparatus as an illumination device in the further embodiment of the invention. In Fig. 3, the same reference symbols are referred to the same portions as Fig.
1. This backlight system 1 has four lamps, but the arrangement may be considered in a similar way. That is, the second and the third lamps 12 and 13 at the central are closer to a portion of the reflector 19 which portion is farthest from the light guide 10. According to this constitution, the parasitic capacitance of four lamps can be equalized effectively, and the same effect as the constitution of Fig. 1 may be obtained. Moreover, even though the reflector is of a half-round shape in the cross section as shown in Fig. 4, the similar effect can be obtained in a similar way. Although only the three and four lamps are explained in the embodiments, the parasitic capacitances can be equalized effectively in the same way also for more lamps. In lamps of the cold cathode discharge tubes in particular, since the inverter circuit for driving the lamps is easily designed and may be advantageous for size reduction. The luminance control is also easy. Since luminance is low as compared with a lamp of the hot-cathode discharge tube, high luminance may be obtained by using many lamps. In such case, the illumination device according to this invention is very suitable.
Moreover, although a rectangle and a half-round shapes have been described in the embodiments, a parabolic shape or a trapezoid shape, for example, may be applicable. Regardless of the cross-section shape of the reflector, the same effect can be obtained by the arrangement for the same parasitic capacitance of all lamps in case of the backlight system using three or more lamps.
Moreover, although the LCD apparatus has been described in the embodiments, the invention should not be limited to the LCD apparatus. This invention is applicable for other kind of display apparatus using the illumination device. Furthermore, although the backlight system of the transmitting-type LCD apparatus with an active matrix type using thin film transistors has been described in the embodiments, the invention is also applicable for an apparatus with a simple matrix type, and it is also applicable for the illumination system as a subsidiary illumination in a reflective type of LCD apparatus. A light reflective plate IR described in the embodiment may be changed in such illumination system.
Effects of The Invention
According to the invention, the same amount of lamp current can be fed when applying the same driving voltage to each light source. Therefore, an approximately uniform luminance can be obtained for each lamp. Moreover, by equalizing a parasitic capacitance of a lamp, an excessive lamp current can be prevented and a life time of a lamp is longer so that the longer life time of products can be realized.
Brief Description of the Drawings Fig. 1 diagramatically shows a paitial section view for a backlight system as an illumination device according to the invention.
Fig. 2 shows a section view for a further embodiment of the backlight system. Fig. 3 shows a partial section view for a further backlight system as an illumination device according to the invention.
Fig. 4 shows a section view for a further backlight system.
Description of Reference Numerals
1 ... backlight system 10 ... light guide plate
IR ... light reflection plate
11-14 ... lamp
19, 19 ... reflector
19a- 19c ... first to third surfaces 2 ... LCD

Claims

CLAIMS:
1. An illumination device for display device, comprising a light guide plate, three or more light sources provided at at least one of side ends of the light guide plate, and a light reflection member, surrounding said light sources, that reflects light emitted from said light sources to said light guide plate, wherein said light sources are provided so as to have the same parasitic capacitance caused by intervals between said light sources and said light reflection member.
2. The illumination device for display device as claimed in Claim 1, wherein at least one of said light sources positioned at the center is closer to an end of said light reflection member farthest from said light guide plate than the other light sources.
3. The illumination device for display device as claimed in Claim 1 or 2, wherein said light reflection member has an opening faced to said side end of said light guide plate, and wherein said light sources are accommodated inside said light reflection member so as to emit light from said opening to said light guide plate.
4. The illumination device for display device as claimed in any one of Claims 1 to 3, wherein said light guide plate is provided on a rear surface side of a display panel of a transmission liquid crystal display device, and has a light reflection layer on a surface on the opposite side to said liquid crystal display device.
5. The illumination device for display device as claimed in any one of Claims 1 to 4, wherein said light sources are elongated lamps provided in approximately parallel to each other along the side end of said light guide plate.
PCT/EP2000/012537 1999-12-17 2000-12-11 Backlight for lcd's WO2001044715A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP00981365A EP1161639B1 (en) 1999-12-17 2000-12-11 Backlight for lcds
DE60040972T DE60040972D1 (en) 1999-12-17 2000-12-11 REAR LIGHTING FOR LIQUID CRYSTAL DISPLAYS
US09/932,102 US7025488B2 (en) 1999-12-17 2001-08-17 Backlight for LCD's

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP35868099A JP4558874B2 (en) 1999-12-17 1999-12-17 Lighting device for display device
JP11/358680 1999-12-17

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US09/932,102 Continuation US7025488B2 (en) 1999-12-17 2001-08-17 Backlight for LCD's

Publications (1)

Publication Number Publication Date
WO2001044715A1 true WO2001044715A1 (en) 2001-06-21

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PCT/EP2000/012537 WO2001044715A1 (en) 1999-12-17 2000-12-11 Backlight for lcd's

Country Status (6)

Country Link
US (1) US7025488B2 (en)
EP (1) EP1161639B1 (en)
JP (1) JP4558874B2 (en)
KR (1) KR100822735B1 (en)
DE (1) DE60040972D1 (en)
WO (1) WO2001044715A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7025488B2 (en) 1999-12-17 2006-04-11 Koninklijke Philips Electronics N.V. Backlight for LCD's
CN100365481C (en) * 2002-11-01 2008-01-30 广辉电子股份有限公司 Back light module

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4045097B2 (en) * 2001-12-28 2008-02-13 シャープ株式会社 Backlight device and liquid crystal display device using the same
JP4115715B2 (en) * 2002-03-01 2008-07-09 シャープ株式会社 Backlight device
KR100855491B1 (en) * 2002-04-12 2008-09-01 엘지디스플레이 주식회사 Apparatus of back light
KR100883094B1 (en) * 2002-07-04 2009-02-11 삼성전자주식회사 Back light assembly and liquid crystal display device using the same
KR100920379B1 (en) * 2002-11-11 2009-10-07 엘지디스플레이 주식회사 Liquid crystal display
KR100912696B1 (en) 2002-12-31 2009-08-19 엘지디스플레이 주식회사 A Back Light
KR100918652B1 (en) * 2003-02-28 2009-09-22 엘지디스플레이 주식회사 Liquid crystal display module
JP4371765B2 (en) * 2003-10-17 2009-11-25 Ｎｅｃ液晶テクノロジー株式会社 Liquid crystal display
US6976767B1 (en) * 2004-01-09 2005-12-20 Tung Hsiung Lin Illumination device having enhanced illuminating effect
US20090190328A1 (en) * 2004-03-23 2009-07-30 Donald Burris Clary Thermal management of lamps in a backlight system
KR20050112905A (en) * 2004-05-28 2005-12-01 엘지.필립스 엘시디 주식회사 Method for control brightness of backlight unit
TWI288851B (en) * 2005-03-09 2007-10-21 Hannstar Display Corp Backlight source module
JP2006344580A (en) * 2005-05-10 2006-12-21 Sony Corp Discharge tube lighting apparatus, light source apparatus and display apparatus
JP4830804B2 (en) * 2006-11-17 2011-12-07 三菱電機株式会社 Planar light source device and display device
CN101276530B (en) * 2007-03-30 2011-07-27 鸿富锦精密工业（深圳）有限公司 Display device as well as method for controlling light source of said display device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1450285A (en) * 1965-10-19 1966-05-06 Poster device
JPH0915595A (en) * 1995-06-30 1997-01-17 Fujitsu Kasei Kk Back light unit
DE29700485U1 (en) * 1997-01-15 1998-03-05 Siemens Ag Flat screen

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2093437A (en) * 1933-12-22 1937-09-21 American Mach & Foundry Cigarette collector
JPH02155595A (en) 1988-12-07 1990-06-14 Meidensha Corp Production of brazing material
JPH0580333A (en) * 1991-09-25 1993-04-02 Hitachi Ltd Back light unit
JPH06222721A (en) * 1993-01-27 1994-08-12 Hitachi Ltd Liquid crystal display device
JP3130402B2 (en) * 1993-02-05 2001-01-31 キヤノン株式会社 Edge type backlight device and liquid crystal device using the same
JPH06301009A (en) * 1993-04-16 1994-10-28 Hitachi Ltd Liquid crystal display device
JPH08138427A (en) * 1994-09-14 1996-05-31 Toshiba Lighting & Technol Corp Surface irradiating device and display device
JPH0982123A (en) * 1995-09-11 1997-03-28 Hitachi Ltd Liquid crystal display device
WO1997012277A1 (en) * 1995-09-27 1997-04-03 Seiko Epson Corporation Display device, electronic appliance and production method of the display device
JPH09230144A (en) * 1996-02-26 1997-09-05 Toshiba Lighting & Technol Corp Back light and liquid crystal display device
JPH09259625A (en) * 1996-03-19 1997-10-03 Sharp Corp Surface light source device and display device provided with the surface light source device
DE69839759D1 (en) * 1997-12-11 2008-09-04 Hunet Display Technology Inc Color display
JP4558874B2 (en) 1999-12-17 2010-10-06 ティーピーオー ホンコン ホールディング リミテッド Lighting device for display device
US6390638B1 (en) * 2000-02-10 2002-05-21 Ide, Inc. Bulb wrap using expanded polytetrafluoroethylene
JP2001351425A (en) * 2000-06-08 2001-12-21 Fujitsu Ltd Backlight device and liquid crystal display device
JP4115715B2 (en) * 2002-03-01 2008-07-09 シャープ株式会社 Backlight device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1450285A (en) * 1965-10-19 1966-05-06 Poster device
JPH0915595A (en) * 1995-06-30 1997-01-17 Fujitsu Kasei Kk Back light unit
DE29700485U1 (en) * 1997-01-15 1998-03-05 Siemens Ag Flat screen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7025488B2 (en) 1999-12-17 2006-04-11 Koninklijke Philips Electronics N.V. Backlight for LCD's
CN100365481C (en) * 2002-11-01 2008-01-30 广辉电子股份有限公司 Back light module

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US7025488B2 (en) 2006-04-11
KR20010102131A (en) 2001-11-15
EP1161639A1 (en) 2001-12-12
JP4558874B2 (en) 2010-10-06
EP1161639B1 (en) 2008-12-03
JP2001184917A (en) 2001-07-06
DE60040972D1 (en) 2009-01-15
KR100822735B1 (en) 2008-04-17
US20010055204A1 (en) 2001-12-27

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